class A{
  final double PI=3.1415926;
   public double getArea(final double r){
   return PI*r*r;
  }
  public final void speak(){
    System.out.println("您好,How's everything here?");
  }
}
public class e5_9{
  public static void main(String args[]){
   A a=new A();
   System.out.println("面积:"+a.getArea(100));
  a.speak();
  }
}
